But cancer risk associated with obesity and lack of physical activity is increasing

Good news from a consortium of organizations led by the National Cancer Institute and Centers for Disease Control and Prevention: Death rates from all cancers combined for men, women, and children continued to decline in the United States between 2004 and 2008, according to the newly released Annual Report to the Nation on the Status of Cancer, 1975-2008.

This woman is not just walking her dog—she's also fighting cardiovascular disease, hypertension, diabetes, and arthritis, as well as many cancers.

The overall rate of new cancer diagnoses, also known as incidence, among men decreased by an average of 0.6 percent per year between 2004 and 2008. Overall cancer incidence rates among women declined 0.5 percent per year from 1998 through 2006 with rates leveling off from 2006 through 2008.

The report is co-authored by researchers from NCI, CDC, the North American Association of Central Cancer Registries (NAACCR), and the American Cancer Society.

At the same time, however, the report notes that increasing obesity rates in the U.S. population is putting a greater number of Americans at risks for obesity-associated cancers. Esophageal adenocarcinoma, cancers of the colon and rectum, kidney cancer, pancreatic cancer, endometrial cancer, and breast cancer among postmenopausal women are associated with being overweight or obese. Several of these cancers also are associated with not being sufficiently physically active.

"This report demonstrates the value of cancer registry data in identifying the links among physical inactivity, obesity, and cancer," said CDC Director Thomas Frieden, MD. "It also provides an update of how we are progressing in the fight against cancer by identifying populations with unhealthy behaviors and high cancer rates that can benefit from targeted, lifesaving strategies, and interventions to improve lifestyle behaviors and support healthy environments."

Link to Increased Cancer Risk

For more than 30 years, excess weight, insufficient physical activity, and an unhealthy diet have been second only to tobacco as preventable causes of disease and death in the United States. However, since the 1960s, tobacco use has declined by a third while obesity rates have doubled, significantly impacting the relative contributions of these factors to the disease burden. Excess weight and lack of sufficient physical activity have been linked to increased risk of cardiovascular disease, hypertension, diabetes, and arthritis, as well as many cancers.

"In the United States, two in three adults are overweight or obese and fewer than half get enough physical activity," said John R. Seffrin, PhD, chief executive officer of the American Cancer Society. "Between children and youth, one in three is overweight or obese, and fewer than one in four high school students get recommended levels of physical activity. Obesity and physical inactivity are critical problems facing all states. For people who do not smoke, excess weight and lack of sufficient physical activity may be among the most important risk factors for cancer."

Decreasing Colorectal and Lung Cancer

The Report to the Nation was first issued in 1998. In addition to drops in overall cancer mortality and incidence, this year's report also documents the second consecutive year of decreasing lung cancer mortality rates among women. Lung cancer death rates in men have been decreasing since the early 1990s.

Colorectal cancer incidence rates also decreased among men and women from 1999 through 2008. Breast cancer incidence rates among women declined from 1999 through 2004 and plateaued from 2004 through 2008. Incidence rates of some cancers, including pancreas, kidney, thyroid, liver, and melanoma, increased from 1999 through 2008.

"The continued declines in death rates for all cancers, as well as the overall drop in incidence, is powerful evidence that the nation's investment in cancer research produces life-saving approaches to cancer prevention, screening, diagnosis, and treatment," said NCI Director Harold Varmus, MD. "But, it is also important to note that investments we make today are critical if we hope to see these declines in incidence and death from cancer reflected in future Reports to the Nation."

Demographic Shifts

Among children ages 19 years or younger, cancer incidence rates increased 0.6 percent per year from 2004 through 2008, continuing trends from 1992, while death rates decreased 1.3 percent per year during the same period. These patterns mirror longer-term trends.

Among racial and ethnic groups, the highest cancer incidence rates between 2004 and 2008 were among black men and white women. Cancer death rates from 2004 through 2008 were highest among black men and black women, but these groups showed the largest declines for the period between 1999 and 2008, compared with other racial groups. The differences in death rates by racial/ethnic group, sex, and cancer site may reflect differences in risk factors, as well as access to and use of screening and treatment.

"While the sustained decline in cancer mortality rates is good news, the persistence of disparities among racial and ethnic groups continues to concern us," said Betsy A. Kohler, executive director of NAACCR. "The collection of comprehensive cancer surveillance data on all patients may provide clues to understanding these differences and addressing them."

The report notes that continued progress against cancer in the United States will require individual and community efforts to promote healthy weight and sufficient physical activity among youth and adults.